.list{
    list-style: none;
    margin: 0px;
    padding: 0px;
    font-size: 13px;
    color: #fff;
    width: 500px;
    margin: 50px auto;
}
.list li{
    float: left;
    width: 100px;
    height: 30px;
    line-height: 30px;
    text-align: center;
    background: #333;
    cursor: pointer;
}